U.S. patent number 10,488,053 [Application Number 15/163,831] was granted by the patent office on 2019-11-26 for apparatus and method for cooling gas cooktop knobs.
This patent grant is currently assigned to BSH Hausgerate GmbH, BSH Home Appliances Corporation. The grantee listed for this patent is BSH Hausgerate GmbH, BSH Home Appliances Corporation. Invention is credited to Ray Briscoe, Conor Cross, Michael Gerdes.
United States Patent |
10,488,053 |
Briscoe , et al. |
November 26, 2019 |
Apparatus and method for cooling gas cooktop knobs
Abstract
A cooktop has a top sheet; a space below the top sheet; a first
passageway through the top sheet; a second passageway through the
top sheet; a first gas burner that draws primary combustion air
from the space below the top sheet; a first gas control knob that
controls an amount of gas that flows to the first gas burner, the
first gas control knob protruding through the first passageway; a
second gas burner that draws primary combustion air from the space
below the top sheet; and a second gas control knob that controls an
amount of gas that flows to the second gas burner, the second gas
control knob protruding through the second passageway. The first
passageway and the second passageway have different airflow rates
at a given negative air pressure in the space below the top
sheet.
Inventors: |
Briscoe; Ray (Havelock, NC),
Cross; Conor (New Bern, NC), Gerdes; Michael (Trent
Woods, NC) |
Applicant: |
Name |
City |
State |
Country |
Type |
BSH Home Appliances Corporation
BSH Hausgerate GmbH |
Irvine
Munich |
CA
N/A |
US
DE |
|
|
Assignee: |
BSH Home Appliances Corporation
(Irvine, CA)
BSH Hausgerate GmbH (Munich, DE)
|
Family
ID: |
60410067 |
Appl.
No.: |
15/163,831 |
Filed: |
May 25, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170343219 A1 |
Nov 30, 2017 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24C
15/006 (20130101); F24C 3/126 (20130101); F24C
15/101 (20130101) |
Current International
Class: |
F24C
15/00 (20060101); F24C 3/12 (20060101); F24C
15/10 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Zanussi, "Zanussi Ultra Flat 5-burner gas hob", Jul. 22, 2013,
http://appliancist.com/cooking/cooktops/zanussi-ultra-flat-5-burner-gas-h-
ob.html. cited by examiner .
Industrial Combustion, "Q-Series", Apr. 24, 2014 (last modified
date of the webpage),
http://www.ind-comb.com/Documents/Brochures/IC-SA-1731%20Q%20Brochure%204-
-2014.pdf. cited by examiner .
Wolf, "Muli Function Cooktop", Dec. 2013,
http://www.subzero-wolf.com/-/media/files/united-states/product-downloads-
/sub-zero-wolf/use-and-care/wolf/multifunction-cooktop-ucg.pdf.
cited by examiner.
|
Primary Examiner: Anderson, II; Steven S
Attorney, Agent or Firm: Tschupp; Michael E. Pallapies;
Andre Braun; Brandon G.
Claims
What is claimed is:
1. A domestic home gas cooktop, comprising: a top sheet; a space
below the top sheet; a first passageway through the top sheet; a
second passageway through the top sheet; a first gas burner that
draws primary combustion air from the space below the top sheet; a
first gas control knob that controls an amount of gas that flows to
the first gas burner, the first gas control knob protruding through
the first passageway; a second gas burner that draws primary
combustion air from the space below the top sheet; and a second gas
control knob that controls an amount of gas that flows to the
second gas burner, the second gas control knob protruding through
the second passageway, wherein the first passageway and the second
passageway have different airflow rates at a given negative air
pressure in the space below the top sheet such that the first gas
control knob and the second gas control knob are subjected to
different cooling as a result of the different airflow rates,
wherein the first passageway is a first hole in the top sheet, and
the second passageway is a second hole in the top sheet, and
wherein the first gas control knob has a skirt that projects
downward from the first gas control knob, the skirt is in a first
position in which a portion of the skirt contacts the top sheet
around a perimeter of the first hole such that the skirt blocks
substantially all air from passing through the first hole when the
first gas control knob is in a gas off position, and the skirt is
in a second position in which the portion of the skirt is separated
from the top sheet such that the skirt allows air to pass through
the first hole when the first gas control knob is in a gas on
position.
2. The domestic home gas cooktop of claim 1, wherein the first hole
has a first hole cross-sectional area, the second hole has a second
hole cross-sectional area, and the first hole cross-sectional area
and the second hole cross-sectional area are different.
3. The domestic home gas cooktop of claim 2, wherein the second
hole is located farther from the first gas burner than the first
hole is located from the first gas burner, and the second hole
cross-sectional area is larger than the first hole cross-sectional
area.
4. The domestic home gas cooktop of claim 2, further comprising a
third passageway through the top sheet; a third gas burner that
draws primary combustion air from the space below the top sheet; a
third gas control knob that controls an amount of gas that flows to
the third gas burner, the third gas control knob protruding through
the third passageway; a fourth passageway through the top sheet; a
fourth gas burner that draws primary combustion air from the space
below the top sheet; a fourth gas control knob that controls an
amount of gas that flows to the fourth gas burner, the fourth gas
control knob protruding through the fourth passageway; a fifth
passageway through the top sheet; a fifth gas burner that draws
primary combustion air from the space below the top sheet; and a
fifth gas control knob that controls an amount of gas that flows to
the fifth gas burner, the fifth gas control knob protruding through
the fifth passageway, wherein each of the passageways has a closest
burner distance that is defined as a distance between that
passageway and the closest one of the burners to that passageway,
the closest burner distance of the third passageway is larger than
the closest burner distance of all others of the passageways, and a
cross-sectional area of the third passageway is larger than a
cross-sectional area of each one of the other passageways.
5. The domestic home gas cooktop of claim 1 further comprising a
first grommet located in the first hole, the first grommet having
an opening having a first grommet cross-sectional area; and a
second grommet located in the second hole, the second grommet
having an opening having a second grommet cross-sectional area,
wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different.
6. The domestic home gas cooktop of claim 5, wherein the first hole
has a first hole cross-sectional area, the second hole has a second
hole cross-sectional area, and the first hole cross-sectional area
is equal to the second hole cross-sectional area.
7. The domestic home gas cooktop of claim 1, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and wherein the
second cross-sectional area is larger than the first
cross-sectional area such that the first gas control knob and the
second gas control knob are subjected to different cooling as a
result of the different airflow rates through the first passageway
and the second passageway at the given negative air pressure in the
space below the top sheet.
8. The domestic home gas cooktop of claim 1, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and the first
cross-sectional area is equal to the second cross-sectional area,
and further comprising a first grommet located in the first
passageway, the first grommet having an opening having a first
grommet cross-sectional area, wherein the first grommet
cross-sectional area of the first grommet is smaller than the
second cross-sectional area of the second passageway such that the
first gas control knob and the second gas control knob are
subjected to different cooling as a result of the different airflow
rates through the first grommet cross-sectional area and the second
passageway at the given negative air pressure in the space below
the top sheet.
9. The domestic home gas cooktop of claim 8, further comprising: a
second grommet located in the second passageway, the second grommet
having an opening having a second grommet cross-sectional area,
wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different such that the first gas
control knob and the second gas control knob are subjected to the
different cooling as a result of the different airflow rates
through the first grommet cross-sectional area and the second
grommet cross-sectional area at the given negative air pressure in
the space below the top sheet.
10. A domestic home gas cooktop, comprising: a top sheet; a space
below the top sheet; a first passageway through the top sheet; a
second passageway through the top sheet; a first gas burner that
draws primary combustion air from the space below the top sheet; a
first gas control knob that controls an amount of gas that flows to
the first gas burner, the first gas control knob protruding through
the first passageway; a second gas burner that draws primary
combustion air from the space below the top sheet; and a second gas
control knob that controls an amount of gas that flows to the
second gas burner, the second gas control knob protruding through
the second passageway, wherein the first passageway and the second
passageway have different airflow rates at a given negative air
pressure in the space below the top sheet such that the first gas
control knob and the second gas control knob are subjected to
different cooling as a result of the different airflow rates,
wherein the first passageway is a first hole in the top sheet, and
the second passageway is a second hole in the top sheet, and
wherein the first gas control knob has a shaft and a disk attached
to the shaft, the disk is in a first position in which a portion of
the disk contacts the top sheet around a perimeter of the first
hole such that the disk blocks substantially all air from passing
through the first hole when the first gas control knob is in a gas
off position, and the disk is in a second position in which the
portion of the disk is separated from the top sheet such that the
disk allows air to pass through the first hole when the first gas
control knob is in a gas on position.
11. The domestic home gas cooktop of claim 10, wherein the disk is
located below the top sheet and is positionaly fixed relative to a
user contact portion of the first gas control knob.
12. The domestic home gas cooktop of claim 10, wherein the first
hole has a first hole cross-sectional area, the second hole has a
second hole cross-sectional area, and the first hole
cross-sectional area and the second hole cross-sectional area are
different.
13. The domestic home gas cooktop of claim 12, wherein the second
hole is located farther from the first gas burner than the first
hole is located from the first gas burner, and the second hole
cross-sectional area is larger than the first hole cross-sectional
area.
14. The domestic home gas cooktop of claim 12, further comprising a
third passageway through the top sheet; a third gas burner that
draws primary combustion air from the space below the top sheet; a
third gas control knob that controls an amount of gas that flows to
the third gas burner, the third gas control knob protruding through
the third passageway; a fourth passageway through the top sheet; a
fourth gas burner that draws primary combustion air from the space
below the top sheet; a fourth gas control knob that controls an
amount of gas that flows to the fourth gas burner, the fourth gas
control knob protruding through the fourth passageway; a fifth
passageway through the top sheet; a fifth gas burner that draws
primary combustion air from the space below the top sheet; and a
fifth gas control knob that controls an amount of gas that flows to
the fifth gas burner, the fifth gas control knob protruding through
the fifth passageway, wherein each of the passageways has a closest
burner distance that is defined as a distance between that
passageway and the closest one of the burners to that passageway,
the closest burner distance of the third passageway is larger than
the closest burner distance of all others of the passageways, and a
cross-sectional area of the third passageway is larger than a
cross-sectional area of each one of the other passageways.
15. The domestic home gas cooktop of claim 10, further comprising:
a first grommet located in the first hole, the first grommet having
an opening having a first grommet cross-sectional area; and a
second grommet located in the second hole, the second grommet
having an opening having a second grommet cross-sectional area,
wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different.
16. The domestic home gas cooktop of claim 15, wherein the first
hole has a first hole cross-sectional area, the second hole has a
second hole cross-sectional area, and the first hole
cross-sectional area is equal to the second hole cross-sectional
area.
17. The domestic home gas cooktop of claim 10, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and wherein the
second cross-sectional area is larger than the first
cross-sectional area such that the first gas control knob and the
second gas control knob are subjected to different cooling as a
result of the different airflow rates through the first passageway
and the second passageway at the given negative air pressure in the
space below the top sheet.
18. The domestic home gas cooktop of claim 10, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and the first
cross-sectional area is equal to the second cross-sectional area,
and further comprising a first grommet located in the first
passageway, the first grommet having an opening having a first
grommet cross-sectional area, wherein the first grommet
cross-sectional area of the first grommet is smaller than the
second cross-sectional area of the second passageway such that the
first gas control knob and the second gas control knob are
subjected to different cooling as a result of the different airflow
rates through the first grommet cross-sectional area and the second
passageway at the given negative air pressure in the space below
the top sheet.
19. The domestic home gas cooktop of claim 18, further comprising:
a second grommet located in the second passageway, the second
grommet having an opening having a second grommet cross-sectional
area, wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different such that the first gas
control knob and the second gas control knob are subjected to the
different cooling as a result of the different airflow rates
through the first grommet cross-sectional area and the second
grommet cross-sectional area at the given negative air pressure in
the space below the top sheet.
20. A domestic home gas cooktop, comprising: a top sheet; a space
below the top sheet; a first passageway through the top sheet; a
second passageway through the top sheet; a first gas burner that
draws primary combustion air from the space below the top sheet; a
first gas control knob that controls an amount of gas that flows to
the first gas burner, the first gas control knob protruding through
the first passageway; a second gas burner that draws primary
combustion air from the space below the top sheet; and a second gas
control knob that controls an amount of gas that flows to the
second gas burner, the second gas control knob protruding through
the second passageway, wherein the first passageway and the second
passageway have different airflow rates at a given negative air
pressure in the space below the top sheet, and wherein the first
gas control knob has a skirt that projects downward from the first
gas control knob, the skirt is in a first position that closes the
first passageway when the first gas control knob is in a gas off
position, and the skirt is in a second position that opens the
first passageway when the first gas control knob is in a gas on
position.
21. The domestic home gas cooktop of claim 20, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and wherein the
second cross-sectional area is larger than the first
cross-sectional area such that the first gas control knob and the
second gas control knob are subjected to different cooling as a
result of the different airflow rates through the first passageway
and the second passageway at the given negative air pressure in the
space below the top sheet.
22. The domestic home gas cooktop of claim 21, wherein the first
passageway is a first hole in the top sheet, and the second
passageway is a second hole in the top sheet.
23. The domestic home gas cooktop of claim 21, wherein the second
hole is located farther from the first gas burner than the first
hole is located from the first gas burner, and the second hole
cross-sectional area is larger than the first hole cross-sectional
area.
24. The domestic home gas cooktop of claim 20, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and the first
cross-sectional area is equal to the second cross-sectional area,
and further comprising: a first grommet located in the first
passageway, the first grommet having an opening having a first
grommet cross-sectional area, wherein the first grommet
cross-sectional area of the first grommet is smaller than the
second cross-sectional area of the second passageway such that the
first gas control knob and the second gas control knob are
subjected to different cooling as a result of the different airflow
rates through the first grommet cross-sectional area and the second
passageway at the given negative air pressure in the space below
the top sheet.
25. The domestic home gas cooktop of claim 24, further comprising:
a second grommet located in the second passageway, the second
grommet having an opening having a second grommet cross-sectional
area, wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different such that the first gas
control knob and the second gas control knob are subjected to the
different cooling as a result of the different airflow rates
through the first grommet cross-sectional area and the second
grommet cross-sectional area at the given negative air pressure in
the space below the top sheet.
26. A domestic home gas cooktop, comprising: a top sheet; a space
below the top sheet; a first passageway through the top sheet; a
second passageway through the top sheet; a first gas burner that
draws primary combustion air from the space below the top sheet; a
first gas control knob that controls an amount of gas that flows to
the first gas burner, the first gas control knob protruding through
the first passageway; a second gas burner that draws primary
combustion air from the space below the top sheet; and a second gas
control knob that controls an amount of gas that flows to the
second gas burner, the second gas control knob protruding through
the second passageway, wherein the first passageway and the second
passageway have different airflow rates at a given negative air
pressure in the space below the top sheet, and wherein the first
gas control knob has a shaft and a disk attached to the shaft, the
disk is in a first position that closes the first passageway when
the first gas control knob is in a gas off position, and the disk
is in a second position that opens the first passageway when the
first gas control knob is in a gas on position.
27. The domestic home gas cooktop of claim 26, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and wherein the
second cross-sectional area is larger than the first
cross-sectional area such that the first gas control knob and the
second gas control knob are subjected to different cooling as a
result of the different airflow rates through the first passageway
and the second passageway at the given negative air pressure in the
space below the top sheet.
28. The domestic home gas cooktop of claim 27, wherein the second
hole is located farther from the first gas burner than the first
hole is located from the first gas burner, and the second hole
cross-sectional area is larger than the first hole cross-sectional
area.
29. The domestic home gas cooktop of claim 26, wherein the first
passageway is a first hole in the top sheet, and the disk closes
the first passageway in the first position by closing the first
hole in the top sheet.
30. The domestic home gas cooktop of claim 26, further comprising:
a first grommet located in the first passageway, the first grommet
having an opening, wherein the disk closes the first passageway in
the first position by closing the opening in the first grommet.
31. The domestic home gas cooktop of claim 26, wherein the first
passageway has a first cross-sectional area and the second
passageway has a second cross-sectional area, and the first
cross-sectional area is equal to the second cross-sectional area,
and further comprising: a first grommet located in the first
passageway, the first grommet having an opening having a first
grommet cross-sectional area, wherein the first grommet
cross-sectional area of the first grommet is smaller than the
second cross-sectional area of the second passageway such that the
first gas control knob and the second gas control knob are
subjected to different cooling as a result of the different airflow
rates through the first grommet cross-sectional area and the second
passageway at the given negative air pressure in the space below
the top sheet.
32. The domestic home gas cooktop of claim 31, further comprising:
a second grommet located in the second passageway, the second
grommet having an opening having a second grommet cross-sectional
area, wherein the first grommet cross-sectional area and the second
grommet cross-sectional area are different such that the first gas
control knob and the second gas control knob are subjected to the
different cooling as a result of the different airflow rates
through the first grommet cross-sectional area and the second
grommet cross-sectional area at the given negative air pressure in
the space below the top sheet.
33. The domestic home gas cooktop of claim 26, wherein the disk is
located below the top sheet and is positionaly fixed relative to a
user contact portion of the first gas control knob.
Description
FIELD OF THE INVENTION
The invention is directed to an apparatus and method related to
optimizing the cooling of knobs on a gas cooktop.
An example of an application for the invention is a domestic
kitchen gas cooktop having improved cooling of the knobs used to
control gas flow.
BACKGROUND OF THE INVENTION
Some modern domestic kitchens include a gas cooktop as either a
countertop mounted cooktop or as a part of a standalone range.
Some domestic cooktops have one or more control knobs that control
the amount of gas that is piped to specific gas burners of the
cooktop. Some cooktops have a top sheet that is formed from, for
example, a piece of sheet steel. The burners protrude through the
top sheet such that the heating flames of the burners exist above
the top sheet. In some of these cooktops, primary combustion air is
drawn from a space below the top sheet and mixed with gas before
being ignited. In some cases, the primary combustion air enters the
space below the top sheet through holes in the top sheet that exist
around shafts of the control knobs.
In some domestic cooktops, the proximity of a control knob to a
burner can result in the temperature of the control knob rising
above an ideal level.
Applicants recognized this problem and developed a solution as
described herein. Applicants also recognized that a control knob
that is relatively close to an active burner can be heated by the
air drawn through the hole in the top sheet because that air is
heated by the burner.
SUMMARY
The invention achieves the benefit of routing primary combustion
air past one or more gas control knobs to cool the control knobs.
The invention achieves this benefit by providing different size
control knob passageways through the top sheet. The passageways can
be the holes in the top sheet through which the control knob shafts
extend. In some embodiments only one passageway has a size that is
different from the other passageways. In other embodiments two or
more passageways have a different size.
For the comfort of the appliance user, a knob cooling strategy can
be very beneficial. In addition, there are government regulatory
limits on control knob temperatures under specified operating
conditions.
Embodiments of the invention are based on the inventors'
recognition that regulating the amount of air allowed to flow
around each of the control knobs and through the top sheet can
positively influence cooling of a particular control knob. This
regulation of the air flow can include regulation of air flow
around a gas control knob that is closest to a particular burner
and/or regulation of air flow around a gas control knob that
controls a particular burner. In particular embodiments, air flow
around any gas control knob in the off position would be prevented
altogether or limited to a greater extent than air flow around any
gas control knob in an on position or vice versa where there is an
advantage to utilize cool air that may be around the knob to cool
the knob when the burner is on.
Several methods can be employed to provide the above described air
flow control. There are active solutions and passive solutions.
Examples of active solutions include a cam activated bezel around
the knob or the knob shaft that opens in an on position of the
control knob and closes in the off position of the control knob.
Other examples of active solutions take advantage of the
often-present feature of the control knob being in different
vertical positions depending on whether the control knob is in an
on position or the off position. In these examples, a damper, for
example a disk, can be attached to the valve shaft of the control
knob such that it moves vertically with the control knob and opens
or closes an opening as a result of that movement. Other
embodiments use a solenoid valve triggered by the rotation of the
gas control knob or a signal from the ignition switch to control
the air flow in the on or off position.
Passive solutions include providing holes of different sizes around
the different control knob shafts. If one control knob tends to be
hotter than others, providing a different size hole around the
shaft of the hotter control knob can provide more cooling air flow
and therefore a cooler control knob.
In determining the optimal air flow for a particular cooktop and/or
situation, the turndown ratio (which is the ratio between the
highest heat and the lowest heat) must be considered. If total air
flow is reduced too far, a low burning flame can be extinguished
(or at least negatively affected) by a lack of sufficient air
flow.
Particular embodiments of the invention are directed to a domestic
home gas cooktop having a top sheet; a space below the top sheet; a
first passageway through the top sheet; a second passageway through
the top sheet; a first gas burner that draws primary combustion air
from the space below the top sheet; a first gas control knob that
controls an amount of gas that flows to the first gas burner, the
first gas control knob protruding through the first passageway; a
second gas burner that draws primary combustion air from the space
below the top sheet; and a second gas control knob that controls an
amount of gas that flows to the second gas burner, the second gas
control knob protruding through the second passageway. The first
passageway and the second passageway have different airflow rates
at a given negative air pressure in the space below the top
sheet.
Other embodiments of the invention are directed to a method of
cooling a gas control knob on a domestic home gas cooktop having a
top sheet, a space below the top sheet, a first passageway through
the top sheet, a second passageway through the top sheet, a first
gas burner that draws primary combustion air from the space below
the top sheet, a first gas control knob that controls an amount of
gas that flows to the first gas burner, the first gas control knob
protruding through the first passageway, a second gas burner that
draws primary combustion air from the space below the top sheet, a
second gas control knob that controls an amount of gas that flows
to the second gas burner, the second gas control knob protruding
through the second passageway. The method includes configuring the
first passageway differently from the second passageway such that
the first passageway and the second passageway have different
airflow rates at a given negative air pressure in the space below
the top sheet; and causing the first gas control knob and the
second gas control knob to be subjected to different cooling as a
result of the different airflow rates.
Particular embodiments include the feature of the first passageway
being a first hole in the top sheet, and the second passageway
being a second hole in the top sheet.
Particular embodiments include the feature of the first hole having
a first hole cross-sectional area, the second hole having a second
hole cross-sectional area, and the first hole cross-sectional area
and the second hole cross-sectional area being different.
Particular embodiments include the feature of the second hole being
located farther from the first gas burner than the first hole is
located from the first gas burner, and the second hole
cross-sectional area being larger than the first hole
cross-sectional area.
Particular embodiments include the feature of each of the
passageways having a closest burner distance that is defined as a
distance between that passageway and the closest one of the burners
to that passageway, the closest burner distance of a particular
passageway being larger than the closest burner distance of all
others of the passageways, and a cross-sectional area of the
particular passageway being larger than a cross-sectional area of
each other passageway.
Particular embodiments include the feature of a first grommet
located in the first hole, the first grommet having an opening
having a first grommet cross-sectional area; and a second grommet
located in the second hole, the second grommet having an opening
having a second grommet cross-sectional area, wherein the first
grommet cross-sectional area and the second grommet cross-sectional
area are different.
Particular embodiments include the feature of the first hole having
a first hole cross-sectional area, the second hole having a second
hole cross-sectional area, and the first hole cross-sectional area
being equal to the second hole cross-sectional area.
Particular embodiments include the feature of the first gas control
knob having a skirt that projects downward from the first gas
control knob, the skirt being in a first position that blocks
substantially all air from passing through the first hole when the
first gas control knob is in a gas off position, and the skirt
being in a second position that allows air to pass through the
first hole when the first gas control knob is in a gas on
position.
Particular embodiments include the feature of the first gas control
knob has a shaft and a disk attached to the shaft, the disk being
in a first position that blocks substantially all air from passing
through the first hole when the first gas control knob is in a gas
off position, and the disk being in a second position that allows
air to pass through the first hole when the first gas control knob
is in a gas on position.
Particular embodiments include the feature of the disk being
located below the top sheet and is positionaly fixed relative to a
user contact portion of the first gas control knob.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures form part of the present specification and
are included to further demonstrate certain aspects of the
disclosed features and functions, and should not be used to limit
or define the disclosed features and functions. Consequently, a
more complete understanding of the exemplary embodiments and
further features and advantages thereof may be acquired by
referring to the following description taken in conjunction with
the accompanying drawings, wherein:
FIG. 1 is a top view of an exemplary cooktop in accordance with
embodiments of the invention;
FIG. 2 is a partial top view of an exemplary embodiment of the
invention;
FIG. 3 is a partial sectional view of an exemplary embodiment of
the invention;
FIG. 4 is a partial top view of an exemplary embodiment of the
invention;
FIG. 5 is a partial sectional view of an exemplary embodiment of
the invention;
FIG. 6 is a partial sectional view of an exemplary embodiment of
the invention in a closed position;
FIG. 7 is a partial sectional view of the embodiment shown in FIG.
6 in an open position;
FIG. 8 is a partial sectional view of an exemplary embodiment of
the invention; and
FIG. 9 is a partial sectional view of an exemplary embodiment of
the invention.
DETAILED DESCRIPTION
The invention is described herein with reference to the
accompanying drawings in which exemplary embodiments of the
invention are shown. The invention may, however, be embodied in
many different forms and should not be construed as limited to the
embodiments set forth herein.
As explained above, embodiments of the invention provide a solution
to the problems associated with elevated temperatures of gas
control knobs on a cooktop.
FIG. 1 shows an example of a cooktop 100 that has a top sheet 120
through which five burners 200 protrude. A control panel 300 has a
gas control knob 500 for each burner 200. In some embodiments, one
gas control knob 500 is mounted to a shaft that protrudes through
top sheet 120 and is connected to a gas flow control valve that is
located below top sheet 120. As shown in FIG. 2, control panel 300
has five holes 310, 320, 330, 340, 350 through which a shaft for
each control knob 500 extends. In this example, each hole 310, 320,
330, 340, 350 is the same size. As shown in FIG. 3, a grommet 410
can be placed in each of hole 310, 320, 330, 340, 350 for esthetic
reasons and/or to help prevent pieces of food, etc., from falling
through the holes and thus through the top sheet.
As explained above, the gas control knobs can become heated by
their proximity to a burner that is burning gas.
As discussed above, primary combustion air can be provided to the
burner from the space below the top sheet. There is often a
box-like structure below the top sheet that contains the lower part
of the burners, a gas manifold, gas control valves, control wiring,
and other parts of the cook top. This box-like structure can be
completely or substantially sealed so that little or no combustion
air is drawn from the space below the cook top. As a result, all or
substantially all of the primary combustion air comes from the area
above the top sheet. One of the ways primary combustion air can
enter the space below the top sheet is by way of the holes through
which the gas control knob shafts extend. This air flow can be used
to cool the gas control knobs.
One way to provide cooling of a particular gas control knob is to
alter the amount of primary combustion air that is drawn through
that control knob's hole in the top sheet. One example of how an
embodiment of the invention provides more air flow for a particular
control knob is shown in FIG. 4. In FIG. 4, hole 332 is larger than
holes 310, 320, 340, 350 and therefore can provide more
airflow.
In some situations, enlarging the hole that is nearest to a
particular burner, for example the front right burner in FIG. 1,
can increase air flow around the control knob associated with that
hole and thus cool that control knob.
In some situations, more air flow through a particular hole can
actually heat the control knob associated with that hole. For
example, if the front right burner in FIG. 1 is lit it is possible
that the control knobs associated with holes 340 and 350 can become
heated. If hole 340 and/or hole 350 is made larger, air heated by
the front right burner can be drawn into the larger hole and
actually increase the temperature of the control knobs associated
with those holes.
As a result of these two situations, burner maximum intensity and
proximity of the control knobs to the burners must be considered
when determining the propper relative size of the holes in the top
sheet.
FIG. 5 shows an example of an active method of controlling air flow
through the top sheet. In FIG. 5 control knob 510 has a
user-contact portion 512 and a skirt 514. Control knob 510 has a
shaft 516 that extends through a hole in top sheet 120. A grommet
410 lines the hole. Similarly, control knob 520 has a user-contact
portion 522 and a skirt 524. Control knob 520 has a shaft 526 that
extends through a hole in top sheet 120. A grommet 420 lines the
hole. Control knobs 510 and 520 are identical except that they are
associated with different holes in the top sheet. Control knob 510
is in the off position, which is the position in which no gas flows
to the burner associated with control knob 510. In contrast,
control knob 520 is in an on position, which is one of the
positions in which gas flows to the burner associated with control
knob 520. As can be seen in FIG. 5, when control knob 520 is an
open position it is raised vertically (Arrow A) as compared to the
off position (as shown by control knob 510). In this or any other
open position, the vertically raised position of control knob 520
allows cooling air to flow along the path of Arrow B and into the
space below the top sheet. The burner that is in an on position
creates a negative pressure by drawing primary combustion air from
the space below the top sheet. This negative pressure draws cooling
air around control knob 520.
FIGS. 6 and 7 show another example of an active method of
controlling air flow through the top sheet. In FIGS. 6 and 7
control knob 610 has a shaft 616 that extends through a hole in top
sheet 120. A disk 618 is fixed to shaft 616 such that it moves
vertically with control knob 610. A grommet 410 lines the hole. In
FIG. 6 control knob 610 is in the off position, which is the
position in which no gas flows to the burner associated with
control knob 610. In FIG. 7 control knob 610 is in an on position,
which is one of the positions in which gas flows to the burner
associated with control knob 610. As can be seen in FIG. 7, when
control knob 610 is an open position it is lower vertically (Arrow
E) as compared to the off position (as shown in FIG. 6). In this or
any other open position, the vertically lower position of control
knob 610 moves disk 618 downward and away from grommet 410, this
allowing cooling air to flow along the path of Arrow C and into the
space below the top sheet. As stated above, the burner that is in
an on position creates a negative pressure by drawing primary
combustion air from the space below the top sheet. This negative
pressure draws cooling air around control knob 610.
An example of a passive method of controlling cooling air flow is
shown in FIGS. 8 and 9. As discussed above with reference to FIG.
4, holes of different sizes can be used to control the relative air
flow through different holes in the top sheet. Enabling the
tailoring of hole size to different models of cooktops without
having to change the size of the holes formed in the top sheet can
reduce production and stocking costs and difficulty. By providing
the top sheet with holes of a uniform size and then providing a
variety of grommet sizes, different hole sizes can be achieved
while simultaneously avoiding having to manufacture multiple
different top sheets. For example, FIGS. 8 and 9 both show hole 310
having a diameter F. However, FIG. 8 shows hole 310 having a
grommet 430 that has an internal hole of diameter G while FIG. 9
shows hole 310 having a grommet 440 that has an internal hole of
diameter H that is smaller than G. By using grommet 440 instead of
grommet 430, the example in FIG. 9 provides a smaller air flow
hole. By inserting the proper size grommets in each of the holes in
a particular application, optimum control knob cooling can be
achieved.
As can be seen in the above exemplary embodiments, the invention
provides solutions to the problems associated with the undesirable
heating of gas control knobs on a gas cooktop.
It will be appreciated that variants of the above-disclosed and
other features and functions, or alternatives thereof, may be
combined into many other different systems or applications. Any of
the features described above can be combined with any other feature
described above as long as the combined features are not mutually
exclusive. Various presently unforeseen or unanticipated
alternatives, modifications, variations or improvements therein may
be subsequently made by those skilled in the art which are also
intended to be encompassed by the invention.
* * * * *
References